Adaptive Music Playback System

ABSTRACT

An adaptive music playback system is disclosed. The system includes a composition system that receives information corresponding to user activity levels. The composition system modifies the composition of a song in response to changes in user activity. The modifications are made according to a set of composition rules to facilitate smooth musical transitions.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 61/772,640, filed Mar. 5, 2013, and titled “AdaptiveMusic Playback System,” which is herein incorporated by reference in itsentirety.

BACKGROUND

The present embodiments relate generally to systems and methods forplaying audio information.

Systems for playing audio information are known in the art. Some suchsystems are portable and may be used by athletes during a workout.Examples of such systems are portable digital audio players as well asmobile phones that include music playback features. Some systems mayfurther incorporate features to facilitate activities, for examplesoftware to map a user's run using GPS information.

SUMMARY

In one aspect, a method of adjusting the playback of audio informationincludes playing a set of audio tracks, retrieving a set of compositionrules and receiving user activity information from at least one sensorconfigured to detect movements of a user and determining a user activitylevel from the user activity information. The method also includesdetermining a target song intensity corresponding to the user activitylevel and controlling the set of audio tracks to achieve the target songintensity.

In another aspect, a method of adjusting the playback of audioinformation includes playing a song, the song including a plurality ofsong segments that are sequential in time and the song furthercomprising a set of audio tracks that may be played simultaneously. Themethod further includes retrieving a set of composition rules, receivinguser activity information from at least one sensor configured to detectmovements of a user and determining a user activity level from the useractivity information while a first song segment is being played. Themethod also includes finding a second song segment with a song statethat matches the user activity level using the composition rules tocompose a musical transition from the first song segment to the secondsong segment.

In another aspect, a method of adjusting the playback of audioinformation includes playing a song, the song including a plurality ofsong segments that are sequential in time. The method also includesreceiving user activity information from at least one sensor configuredto detect movements of a user and determining a user activity level fromthe user activity information while a first song segment is beingplayed. The method also includes finding a second segment of the songwith a song state that matches the user activity level. The method alsoincludes retrieving a universal transition segment, where the universaltransition segment can be played in sequence with any of the pluralityof song segments without creating abrupt musical transitions. The methodalso includes playing the universal transition segment after the firstsong segment and playing the second song segment after the universaltransition segment in order to create a transition between the firstsegment and the second segment.

Other systems, methods, features and advantages of the embodiments willbe, or will become, apparent to one of ordinary skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be included within this description and this summary, bewithin the scope of the embodiments, and be protected by the followingclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the embodiments. Moreover, in the figures, likereference numerals designate corresponding parts throughout thedifferent views.

FIG. 1 is a schematic view of an embodiment of an adaptive musicplayback system;

FIG. 2 is a schematic view of a general process for creating musicalcompositions for playback using sensory input and music information;

FIG. 3 is a schematic view of an embodiment of some types of musicinformation;

FIG. 4 is a schematic view of an embodiment of a song comprisingindividual instrument and vocal tracks;

FIG. 5 is an embodiment of a process for adjusting the composition of asong in response to user activity;

FIG. 6 is a schematic view of an embodiment of several inputs used foradjusting the composition of a song;

FIG. 7 is an embodiment of a detailed process for adjusting thecomposition of a song;

FIG. 8 is an embodiment of a process for composing a musical transition;

FIG. 9 is a schematic view of several instrument and vocal tracks at twomeasures having different intensities;

FIG. 10 is a schematic view of several instrument and vocal tracks attwo measures having different intensities, in which a transition hasbeen generated between the measures;

FIG. 11 is a schematic view of several instrument and vocal tracks attwo measures having different intensities;

FIG. 12 is a schematic view of several instrument and vocal tracks attwo measures having different intensities, in which a transition hasbeen generated between the measures;

FIG. 13 is an embodiment of a process for modifying individual tracks ina song segment to achieve a desired song intensity;

FIG. 14 is a schematic view of an embodiment of a portion of a song withdifferent tracks faded in and out according to the activity level of auser;

FIG. 15 is a schematic view of an embodiment of a portion of a song,including a shortest path from a low intensity song segment to a highintensity song segment;

FIG. 16 is an embodiment of a process for generating a shortest sequenceof musical segments between two segments of different intensity levels;

FIG. 17 is a schematic view of an embodiment of a song divided into manysegments and a universal transition that provides a direct path betweenany two segments; and

FIG. 18 is a schematic view of an embodiment of a song divided into manysegments and a universal transition that provides a direct path betweenany two segments.

DETAILED DESCRIPTION

FIG. 1 is a schematic view of an embodiment of an adaptive musicplayback system 100. Adaptive music playback system 100 may generallycomprise one or more sub-systems, components or devices for adapting theplayback of music according to one or more inputs. More specifically,adaptive music playback system 100 may generally be used to adjust theplayback of music according to changes in the state of an associateduser and/or associated system. For example, the following embodimentsdiscuss systems and methods for adjusting playback of a song usinginformation that characterizes the activity level (i.e., the activitystate) of a user. However, the embodiments are not intended to belimiting, and other embodiments could include systems and methods usedto adjust the playback of music according changes in other kinds of userstates, such as various biometric states, mental and/or emotional states(e.g., user mood) or other kinds of states.

In some embodiments, adaptive music playback system 100 may furtherinclude a composition system 102, sensor system 104 and transducersystem 110. For purposes of clarity, transducer system 110 is shownschematically in the embodiments. Generally, transducer system 110 mayinclude any number, type and/or arrangement of transducers. Moreover,transducer system 110 may be further associated with provisions forsupporting and positioning the transducers (i.e., housings, casings,clips, etc.). In some embodiments, transducer system 110 could includeone or more loudspeakers. In other embodiments, transducer system 110could comprise headphones that may be worn by a user.

Sensor system 104 may comprise one or more sensors, as well asprovisions for storing and positioning the sensors. As one example, theschematic sensor system 104 of FIG. 1 depicts a system including a firstsensor 105 and a second sensor 106. Although this embodiment depicts asensor system with two separate sensors, other embodiments may includeany number of sensors including one, two, three, four or more sensors.

Sensor system 104 may be configured to detect information associatedwith the state of a user. In some embodiments, sensor system 104 maydetect information related to the motion and/or activity of the user. Inother embodiments, sensor system 104 could detect other informationincluding the position of a user (e.g., global position and relativeposition), biometric information (e.g., heart rate, respiratory rate,perspiration level, etc.), as well as other kinds of information.

Generally, sensors of sensor system 104 may be positioned in any mannerrelative to a user. In some embodiments, sensor system 104 may bedirectly attached to a user using clips, bands or similar provisions. Inother embodiments, sensor system 104 may be disposed within, orotherwise associated with, portions of an article of footwear, anarticle of apparel and/or an item of sporting equipment. In someembodiments, each sensor of sensor system 104 may be associated withcorresponding articles of footwear. For example, in the schematicembodiment of FIG. 1, first sensor 105 and second sensor 106 are furtherassociated with a first article of footwear 107 and a second article offootwear 108, respectively. By positioning each sensor within an articleof footwear, first sensor 105 and second sensor 106 can be used todetect user motion and/or activity as the user walks, runs, jumps orperforms other kinds of activities. Thus, for example, sensor system 104could detect a user's walking or running pace, which may be used tocharacterize a level of user activity as discussed in further detailbelow.

Embodiments can use a variety of different sensors capable of sensinginformation related to a variety of different physical motions, as wellas physical and/or biological states. The embodiments may incorporateone or more of the sensors, features, systems, devices, components,methods and/or sensed information disclosed in the following documents:Case et al., U.S. Pat. No. 8,112,251, issued Feb. 7, 2012; Riley et al.,U.S. Pat. No. 7,771,320, issued Aug. 10, 2010; Darley et al., U.S. Pat.No. 7,428,471, issued Sep. 23, 2008; Amos et al., U.S. PatentApplication Publication Number 2012/0291564, published Nov. 22, 2012;Schrock et al., U.S. Patent Application Publication Number 2012/0291563,published Nov. 22, 2012; Meschter et al., U.S. Patent ApplicationPublication Number 2012/0251079, published Oct. 4, 2012; Molyneux etal., U.S. Patent Application Publication Number 2012/0234111, publishedSep. 20, 2012; Case et al., U.S. Patent Application Publication Number2012/0078396, published Mar. 29, 2012; Nurse et al., U.S. PatentApplication Publication Number 2011/0199393, published Aug. 18, 2011;Hoffman et al., U.S. Patent Application Publication Number 2011/0032105,published Feb. 10, 2011; Schrock et al., U.S. Patent ApplicationPublication Number 2010/0063778, published Mar. 11, 2010; Shum, U.S.Patent Application Publication Number 2007/0021269, published Jan. 25,2007; Schrock et al., U.S. patent application Publication Ser. No.______, now U.S. patent application Ser. No. 13/401,918, filed Feb. 22,2012, titled “Footwear Having Sensor System”; Schrock et al., U.S.patent application Publication Ser. No. ______, now U.S. patentapplication Ser. No. 13/401,910, filed Feb. 22, 2012, titled “FootwearHaving Sensor System”, where the entirety of each document isincorporated by reference herein.

Although the embodiment shown in FIG. 1 illustrates sensor systemsincorporated into footwear, other embodiments could include sensorsincorporated into any other articles of apparel. For example, some otherembodiments could have one or more sensors incorporated into pants,shirts, socks, hats, gloves as well as possibly other articles ofapparel. Moreover, in some other embodiments, one or more sensors couldbe incorporated into items of sporting equipment including, but notlimited to: bats, balls, gloves, golf clubs, pads, helmets, as well aspossibly other kinds of sporting equipment.

Composition system 102 may include various provisions for receivingsensory information and adapting music information for playback throughone or more transducers. Methods of adjusting playback of one or moresongs and/or sounds are discussed in further detail below.

Generally, composition system 102 can comprise a variety of differentsystems, components and/or devices. Exemplary systems may includecomputing systems or portions of computing systems. These computingsystems may include hardware such as memory, processors, and possiblynetworking provisions. Moreover, in some embodiments, composition system102 may also run software for composing music information into songs, orportions of songs, for playback.

In some embodiments, some components of composition system 102 could behoused in a portable playback device. Exemplary devices include, but arenot limited to: smartphones (e.g., the iPhone), digital music players(e.g. the iPod) as well as possibly other portable playback devices. Inone exemplary embodiment, provisions of composition system 102 may beincorporated into a smartphone or a digital music player, which mayadjust playback of a song according to information received from one ormore sensors.

In some embodiments, provisions of composition system 102 for analyzingsensor information and adjusting playback of a song may run directly ona portable playback device. For example, software for receiving sensorinformation and adjusting playback of a song accordingly could beimplemented as an application on a smartphone. However, in otherembodiments provisions may be incorporated into separate components ordevices. For example, in another embodiment, analysis of sensorinformation and adjustment of song playback could occur at a remotecomputing device (e.g., a laptop or desktop computer), which thencommunicates with a portable device (e.g., a digital music player) forplayback. Moreover, communication between separate sub-systems,components and/or devices of composition system 102 could be implementedusing wired or wireless provisions.

Composition system 102 may include a number of ports that facilitate theinput and output of information and power. The term “port” as usedthroughout this detailed description and in the claims refers to anyinterface or shared boundary between two conductors. In some cases,ports can facilitate the insertion and removal of conductors. Examplesof these types of ports include mechanical connectors. In other cases,ports are interfaces that generally do not provide easy insertion orremoval. Examples of these types of ports include soldering or electrontraces on circuit boards.

All of the following ports and provisions associated with compositionsystem 102 are optional. Some embodiments may include a given port orprovision, while others may exclude it. The following descriptiondiscloses many of the possible ports and provisions that can be used,however, it should be kept in mind that not every port or provision mustbe used or included in a given embodiment.

In some embodiments, composition system 102 may include port 112 forreceiving information from one or more sensors. In some cases, port 112is configured to receive information from sensor system 104. Inembodiments where a wireless connection is provided between compositionsystem 102 and sensor system 104, wireless communication could befacilitated using any known methods of wireless communication. Likewise,composition system 102 may include port 114 for transmitting informationto transducer system 110. Thus, signals may be sent to transducer system110 via port 114 in order to facilitate playback of a song and/or othersounds.

FIG. 2 shows a general process of receiving information, processinginformation and playing audio information corresponding to the processedinformation. More specifically, information from sensor system 104 isreceived along with music information 204 for processing. A compositioncan then be created from the music information 204 in response to thesensory information from sensor system 104 (which may be indicative ofuser activity) at step 206. The output of this composition process isaudio information that can be played at step 208.

Throughout the detailed description and in the claims the term “musicinformation” may refer to various kinds of information related to aparticular song, portions of a song (segments or sections), tracks of asong, samples, as well as any other kinds of information. In some cases,music information could also include information about two or moresongs, including playlist information that controls flow throughmultiple songs. More generally, then, music information may refer to anyinformation used to generate songs with a playback device.

The embodiments illustrate some methods of composing music information,including mixing individual tracks to create new compositions. However,in some cases, composing music information may include ordering songs ina playlist. For example, in some other embodiments, a system may beconfigured to organize a sequence of songs for playback according tovarious music selection parameters. Other embodiments could use any ofthe systems, components, devices, and methods for automatically creatinga sequence of songs for playback (e.g., generating a playlist orordering songs in a playlist) that are disclosed in Johnson, U.S. PatentApplication Publication Number 2010/0273610, now U.S. patent applicationSer. No. 12/768,168, filed Apr. 27, 2010 and titled “Training Programand Music Playlist Generation for Athletic Training,” the entirety ofwhich is herein incorporated by reference.

FIG. 3 illustrates a schematic view of some types of music information,according to an embodiment. It will be understood that FIG. 3 is onlyintended to illustrate some kinds of music information and otherembodiments could include additional types of music information.Likewise, some types of music information shown here may be optional inother embodiments.

Music information 204 may include sample information 302. Sampleinformation 302 may include samples for various instruments, voicesand/or other sounds that can be stored as individual sound files. As anexample, sample information 302 may further include guitar sample 310,drum sample 312, keyboard sample 314 and voice sample 316. Other sampleinformation corresponding to additional instruments, voices and soundscould also be included in some embodiments. The term “sample” is notintended to be limiting and could include any collection of informationrelated to a particular instrument, voice, or other kind of sound.

Some embodiments may make use of MIDI (Musical Instrument DigitalInterface) information 304 (including MIDI streams or other MIDI fileinformation). For example, some songs could store a MIDI stream for oneor more instruments. When paired with an instrument, voice or soundsample file, the MIDI stream may provide instructions for playing asequence of notes corresponding to the selected instrument, voice orsound sample file. Thus, MIDI information 304 may be used to storearrangements of sample sounds. In some cases, each MIDI stream maycorrespond to a track in a multi-track song, or a portion of a track ina multi-track song.

Some embodiments may also utilize recorded audio information 306.Generally, recorded audio information 306 may generally comprise full orpartial length audio recordings, which may be stored as recorded audiofiles. For example, a first recorded audio file 320 may correspond tothe audio recording of a guitar playing through the entire length of asong. Likewise, a second recorded audio file 322 may correspond to theaudio recording of a vocalist singing through the entire length of asong. As discussed in further detail below, these recorded audio filesmay each serve as an individual track in a multi-track song.

It will be understood that each different type of music information(e.g., sample information, MIDI stream information, recorded audioinformation as well as any other kinds of music information) can bestored in a variety of different formats. For example, recorded audioinformation could be stored using any formats including, but not limitedto: uncompressed audio formats (such as WAV, AIFF, AU or PCM), formatswith lossless compression (such as FLAC, WavPack, Monkey Audio format,WMA Lossless or MPEG-4 SLS), formats with lossy compression (such asMP3, AAC or WMA lossy) as well as any other kinds of known audioformats. Moreover, any music information files can be used incombination with one or more audio codecs for encoding and decoding rawaudio data. Still further, MIDI stream information could be stored usingany known MIDI formats, including the Standard MIDI File (SMF) format.Sample information could likewise be stored using any of the formatsdiscussed with regards to recorded audio information.

Embodiments of music information 204 can also include a set ofcomposition rules 350. The term “composition rules” as used throughoutthis detailed description and in the claims refers to any informationthat may be used to determine how different audio tracks, or otherpieces of music information, may be combined in response to changes inthe state of an external system or user (e.g., in response to theincrease/decrease in a user's activity level). For clarity, individualcomposition rules in the set of composition rules 350 may be furtherclassified as predetermined rules 352 or user preferences 354.Predetermined rules 352 may comprise rules that are pre-programmed andmay correspond to general composition rules associated with combiningdifferent instruments, voices and sounds in a manner that preserves adesired level of musical coherence and limits abrupt musicaltransitions. Thus, predetermined rules 352 could include, for example,rules for determining which instruments should exit or enter acomposition first, as well as which combinations of instruments may playtogether or not play together. In some cases, predetermined rules 352could be generic so that similar rules are used with different songs. Inother cases, predetermined rules 352 may be specific for each individualsong played. In still other cases, predetermined rules 352 may be acombination of both generic rules and song specific rules.

User preferences 354 may comprise composition rules that may be adjustedby a user. For example, user preferences 354 could include a maximumvolume setting that prevents one or more tracks from being played backat a volume above the maximum volume setting. As another example, userpreferences 354 could include settings to indicate whether the userwants to progress more rapidly through a song, or if the user may notmind repeating portions of the song many times. Another example of auser preference may be a preference for a certain style of music, suchas a preference for lots of individual instrument or vocal solos.

The number and type of composition rules may vary from one embodiment toanother, and may be generally selected to achieve harmonious transitionsbetween different portions of a song having different overallintensities (or possibly other different characteristics). It will alsobe understood that composition rules 350 need not be organizedseparately into predetermined rules 352 and user preferences 354 inother embodiments.

FIG. 4 is a schematic view of an embodiment of a portion of a song, asrepresented by several instrument/vocal audio tracks and a master audiotrack (or simply, master track). Referring to FIG. 4, a portion of asong may comprise four different audio tracks, including guitar track402, drum track 404, keyboard track 406 and vocal track 408. Althoughrepresented schematically here using musical notation, each audio trackmay be stored as an individual audio sound file or as a MIDI stream.Moreover, guitar track 402, drum track 404, keyboard track 406 and vocaltrack 408 may comprise part of a master track 410, which results fromthe combination of all the different audio tracks.

For purposes of illustration, master track 410 is indicatedschematically in FIG. 4 using waveforms, though it will be understoodthat master track 410 is composed of each of the individual soundscorresponding to the instruments and notes indicated in guitar track402, drum track 404, keyboard track 406 and vocal track 408.

As seen here, master track 410 can be divided into individual sectionsor segments. As used throughout this detailed description and in theclaims, the term “segment” refers to a generally continuous portion of asong with a beginning and an end. Thus, a song may be divided intoseparate segments, which may be sequential in time. For example, thesong portion shown in FIG. 4 can include a first song segment 420, asecond song segment 422 and a third song segment 424. Each song segmentmay be characterized by a beginning and an end. In situations wheremaster track 410 is indexed using time, first song segment 420 may beginat time T1 and end at time T2. Second song segment 422 may begin at timeT2 and end at time T3. Furthermore, third song segment 424 may begin attime T3 and end at time T4. Although the current embodiments use time asmeans for indexing different points of master track 410, otherembodiments could use any other methods of indexing a song. Moreover,the method of defining one or more segments may vary. In some cases, forexample, a segment could correspond to a measure of music, or to apredetermined number of measures. In other cases, a segment could bedetermined by identifying changes in one or more characteristics of asequence of audio information, such as changes in the audio waveform. Itwill also be understood that different segments could have the samelength or could have different lengths according to the method ofdefining each segment.

In the embodiment of FIG. 4, each of first song segment 420, second songsegment 422 and third song segment 424 are associated with an intensitylevel. In particular, first song segment 420 is characterized as a lowintensity segment, second song segment 422 is characterized as a highintensity segment and third song segment 424 is characterized as amedium intensity segment.

In still other embodiments, segments of a song can be identified withother musical criteria including, but not limited to, characterizing thesegments by key, pitch, loudness, tempo, as well as possibly othermusical criteria. Moreover, in some cases, individual tracks couldlikewise be divided into segments characterized according to key, pitch,loudness, tempo as well as possibly other musical criteria.

FIG. 5 illustrates an embodiment of a process for adjusting thecomposition of a song, or otherwise adjusting the playback of a song,according to detected changes in user activity. In some embodiments,some of the following steps could be accomplished by composition system102 (see FIG. 1). In other embodiments, some of the steps could beaccomplished by any other components, systems or devices associated withadaptive music playback system 100. It will be understood that in otherembodiments one or more of the following steps may be optional.

At step 502, composition system 102 may start playing a song. This mayoccur in response to user input, such as a user pressing play on adigital music device, or in response to other kinds of input such asuser motion. Next, in step 504, composition system 102 may receive inputfrom one or more sensors (e.g., one or both of the sensors of sensorsystem 104).

During step 504, the information from one or more sensors may be used todetermine a current activity level for the user. The term “activitylevel” as used throughout this detailed description and in the claimsrefers to a value or set of values for characterizing user activity oruser motion including, but not limited to, user speed, useracceleration, user position, user gait, user stride, ground contactforce as well as possibly other characterizations of user activity. Insome cases, the user activity level may be determined by considering acombination of such factors. The activity level may take on continuevalues, for example, a continuous value in the range of 0 (leastactivity) to 10 (greatest activity). The activity level may also take ondiscrete values. For example, some embodiments could utilize a threevalue activity level scale, with “low activity”, “moderate activity” and“high activity” values.

At step 506, composition system 102 may compare the activity leveldetermined in step 504 with the current song state. The song state maygenerally be characterized according to any known factors, including butnot limited to: intensity, tempo, complexity, key, and pitch as well aspossibly other factors. In some embodiments, the song state maygenerally refer to song intensity, which could be one of low intensity,medium intensity or high intensity. However, other embodiments could useany other methods for characterizing the song state, including any ofthe factors listed above as well as any combination of these factors.The embodiments described here may generally use a notion of song statethat can be matched with user activity levels. For example, various songintensities could be matched with corresponding user activity levels.

In step 508, composition system 102 may determine if the user activitylevel matches the current song state. For example, composition system102 may determine if the current user activity level matches the currentsong intensity (i.e., the intensity of the song segment currently beingplayed). If there is a match, composition system 102 proceeds to step510 and may continue playing the song without any adjustments. However,if there is a mismatch between the activity level and the current songstate, composition system 102 may proceed instead to step 512. At step512, composition system 102 may adjust the composition by changing to adifferent song segment and/or adjusting the composition of one or moreaudio tracks. Various methods for accomplishing this compositionadjustment are discussed in further detail below.

As seen in FIG. 6, several factors may be considered by compositionsystem 102 in order to determine how to adjust the song composition.Specifically, any process of adjusting the composition of a song,indicated schematically as process 608, may use one or more inputs.These include user activity 602, composition rules 604 and the currentsong state 606. In particular, user activity 602 and current song state606 may be monitored continuously. When user activity 602 and currentsong state 606 are mismatched, the composition may then be adjusted in amanner determined by composition rules 604.

FIG. 7 illustrates an embodiment of a process for adjusting thecomposition of a song, or otherwise adjusting the playback of a song,according to detected changes in user activity. In some embodiments,some of the following steps could be accomplished by composition system102 (see FIG. 1). In other embodiments, some of the steps could beaccomplished by any other components, systems or devices associated withadaptive music playback system 100. It will be understood that in otherembodiments one or more of the following steps may be optional.

At step 702, composition system 102 may determine the current activitylevel of the user. This may be done by analyzing information from one ormore sensors. Next, in step 704, composition system 102 may find a newsegment of the song that has a song state that matches the current useractivity level. For example, composition system 102 may find a segmentof a song with an intensity corresponding to the current activity level.In some cases, this could be accomplished by performing a real-timeanalysis of the audio information to find a segment with a matchingintensity. In other cases, intensity levels for different song segmentscould be stored in a table or database for easy retrieval.

Generally, the system may be configured to associate activity level withintensity. For example, a high user activity level that is greater thansome threshold may correspond to a high intensity. Any method fordetermining an intensity from a user activity level could be used. Insome embodiments, a function or table may be used to automatically mapuser activity levels to corresponding intensities, where the inputs(user activity level) and the outputs (intensity) could be continuousand/or discrete values.

In step 706, composition system 102 may determine if it is ok to jumpdirectly to the new segment having an intensity corresponding to thecurrent user activity level. Such a decision could be made by comparingvarious musical characteristics of the current segment withcharacteristics of the new segment. If it is determined that there isalready a good musical match between the current segment and the newsegment, composition system 102 may determine that it is ok to directlyjump to the new segment and proceed to step 708. At step 708,composition system 102 determines that no musical transition is neededand proceeds to step 710, where composition system 102 may jump to thenew segment.

However, if during step 706 composition system 102 determines thatjumping directly to the new segment is not desirable, composition system102 proceeds to step 712. In step 712 composition system 102 determinesthat a musical transition is needed between the current song segment andthe new song segment. At step 714, therefore, composition system 102proceeds to compose the necessary musical transition.

FIG. 8 illustrates some possible steps in the process of composing amusical transition. During a step 802, composition system 102 may selecta general transition type. For example, composition system 102 maydetermine if an attack type pattern 804 is needed or if a decay typepattern 806 is needed. In situations where the current song segment hasa low musical intensity and the new song segment has a high musicalintensity, composition system 102 may select an attack pattern, whichgenerally allows for the gradual introduction of audio tracks during thetransition. In situations where the current song segment has a highmusical intensity and the new song segment has a low musical intensity,composition system 102 may select a decay pattern, which generallyallows for the gradual removal of audio tracks during the transition.While the embodiment illustrates two basic kinds of transition patterns,namely attack patterns and decay patterns, other embodiments couldincorporate any number of predetermined transition patterns includinglinear patterns, non-linear patterns as well as any other knowntransition patterns or combinations of known transition patterns.

Once a general transition type has been selected in step 802,composition system 102 may proceed to step 808. At step 808, compositionsystem 102 may compose a transition score to join the segments. Inparticular, this process may make use of composition rules 810 todetermine the timing of entry and/or exit of different audio tracksthroughout the transition. This process may also use composition rules810 to determine the relative volume settings of different audio tracksthroughout the transition.

FIG. 9 illustrates a schematic view of at least some tracks in a portionof a song 900. The portion of song 900 includes lead guitar track 902,rhythm guitar track 904, keyboard track 906, bass track 908, drum track910 and vocal track 912. For purposes of illustration, each track isindicated schematically by an instrument and an associated sequence ofmusical notes. However, it will be understood that the music informationrepresenting each track could be stored (and analyzed) in a variety offormats.

FIG. 9 is intended to schematically indicate a configuration in which amusical transition is needed to move from measure 15 of song 900 tomeasure 35, bypassing some or all of the measures between measure 15 andmeasure 35. In this case, measure 15 may be characterized as having amoderate intensity, in contrast to measure 35, which has a highintensity. The need to create such a transition could arise if the useractivity level rises from a moderate level (matching well with measure15) to a high level (matching well with measure 35) while measure 15 isbeing played.

FIG. 10 illustrates one possible way of generating a musical transitionto move from measure 15 to measure 35 by timing the entrance of one ormore tracks. In this example, two extra copies of measure 35 (referredto as first transition measure 920 and second transition measure 922)are used as the basis of the transition. Moreover, composition rules 350(see FIG. 3) may be used to determine which tracks are played duringthese two extra measures.

In some embodiments, decisions to mute or unmute tracks (i.e., controlthe entrance and exit of tracks) can be based on one or more generalpatterns, such as attack patterns or decay patterns. As seen in FIG. 10,transition line 930 represents an idealized transition pattern forunmuting tracks as the song progresses from the end of measure 15 to thebeginning of measure 35. Such a transition pattern may therefore serveas a first approximation or guide to gradually increasing the intensityof the song. However, to ensure that there is musicalcontinuity/coherence and to reduce abrupt changes in instruments andsounds, composition rules 350 may be used to ensure each track enters orexits the song at preferred times. For example, rather than having atrack enter in the middle of a measure, composition rules 350 may beused to ensure a full measure is played (or muted) in order to preservethe musical integrity of each audio track and harmony between audiotracks.

As seen in FIG. 10, lead guitar track 902, rhythm guitar track 904,keyboard track 906 and bass track 908 are muted during first transitionmeasure 920, while drum track 910 and vocal track 912 are played. Sincedrum track 910 is unchanged from measure 15 to measure 35, playing drumtrack 910 through first transition measure 920 and second transitionmeasure 922 provides musical continuity. Likewise, vocal track 912 mayplay through first transition measure 920 and second transition measure922 if it is determined that transition in vocals from measure 15 tomeasure 35 is musically harmonious and not too abrupt. As the songprogresses to second transition measure 922 additional tracks are addedin rough (but not exact) correspondence to transition line 930. Inparticular, keyboard track 906 and bass track 908 are added duringsecond transition measure 922 to increase the intensity gradually, whilemaintaining the musical integrity of the song. Finally, in progressingto the original measure 35, lead guitar track 902 and rhythm guitartrack 904 are added to provide the high intensity sound of measure 35.

FIG. 11 is intended to schematically indicate another configuration inwhich a musical transition is needed to move from measure 55 of song 900to measure 75, bypassing some or all of the measures between measure 55and measure 75. In this case, measure 55 may be characterized as havinga moderate intensity, in contrast to measure 75, which has a lowintensity. The need to create such a transition could arise if the useractivity level decreases from a moderate level (matching well withmeasure 55) to a low level (matching well with measure 75) while measure55 is being played.

FIG. 12 illustrates one possible way of generating a musical transitionto move from measure 55 to measure 75 by timing the entrance of one ormore tracks. In this example, two extra copies of measure 55 (referredto as third transition measure 940 and fourth transition measure 942)are used as the basis of the transition. Moreover, composition rules 350(see FIG. 3) may be used to determine which tracks are played duringthese two extra measures.

In some embodiments, decisions to mute or unmute tracks (i.e., controlthe entrance and exit of tracks) can be based on one or more generalpatterns, such as attack patterns or decay patterns. As seen in FIG. 12,transition line 950 represents an idealized transition pattern forunmuting tracks as the song progresses from the end of measure 55 to thebeginning of measure 75. Such a transition pattern may therefore serveas a first approximation or guide to gradually reducing the intensity ofthe song. However, to ensure that there is musical continuity and reduceabrupt changes in instruments and sounds, composition rules 350 may beused to ensure each audio track enters or exits the song at preferredtimes. For example, rather than having a track enter in the middle of ameasure, composition rules 350 may be used to ensure a full measure isplayed (or muted) in order to preserve the musical integrity of eachaudio track and harmony between audio tracks.

As seen in FIG. 12, lead guitar track 902 and rhythm guitar track 904are muted in third transition measure 940 to help gradually lower theintensity. As the song progresses to fourth transition measure 942,keyboard track 906 and bass track 908 are muted. As the song progressesto the original measure 75, all tracks are unmuted. Specifically, leadguitar track 902, rhythm guitar track 904, keyboard track 906 and basstrack 908 all enter again at measure 75, as the combination of all thesetracks at measure 75 results in the desired low intensity sound.

Embodiments can include provisions to adjust song intensity withoutchanging song segments. In some embodiments, one or more audio trackscould be controlled to enter and/or exit the song so that the intensityof the current segment is modified to match the user activity level.

FIG. 13 illustrates an embodiment of a process for controlling thefading in and out (or entry and exit) of audio tracks throughout acontinuous segment of a song. As previously discussed, some or all ofthe following steps could be accomplished by composition system 102, aswell as any other associated systems, components or devices.

In step 1302, composition system 102 may determine the current activitylevel. This may be determined by analyzing information from one or moresensors. Next, in step 1304, composition system 102 may determine atarget song intensity to match the activity level detected in step 1302.Following this, in step 1306, composition system 102 may determine ifthe target song intensity can be achieved by modifying the current songsegment. If not, composition system 102 may proceed to step 1308. Atstep 1308, composition system 102 may search for a new song segment withthe desired target song intensity.

If in step 1306, composition system 102 determines that the target songintensity can be achieved by modifying the current song segment,composition system 102 may proceed to step 1312. In step 1312,composition system 102 uses composition rules 1310 to control individualaudio tracks so that the target song intensity is achieved. Inparticular, composition system 102 may control the fading in and out ofvarious tracks to achieve the target song intensity within the currentsong segment, rather than jumping to another song segment.

FIG. 14 illustrates schematically how a composition system may fadeaudio tracks in and out of a particular song segment or passageaccording to user activity (and using a set of composition rules).Referring to FIG. 14, song 1400 includes lead guitar track 1402, rhythmguitar track 1404, keyboard track 1406, bass track 1408, drum track 1410and vocal track 1412. In this embodiment, each audio track isrepresented schematically as a waveform or sound signal. For example,each audio track shown here may represent an individual audio file for acorresponding instrument.

Also shown in FIG. 14 are different configurations of a schematic mixingboard, including a first mixing board configuration 1420, a secondmixing board configuration 1422 and a third mixing board configuration1424. Likewise, a user of adaptive music playback system 100 is seen ina first user state 1430, a second user state 1432 and a third user state1434 that correspond to a low activity level, a moderate activity leveland a high activity level, respectively.

FIG. 14 shows how the song state, including which tracks are played andwhich tracks are muted, changes in response to user activity. In thefirst user state 1430, the user may be walking and therefore has a lowactivity level. To accommodate the low activity level of the user,composition system 102 mutes lead guitar track 1402, keyboard track 1406and bass track 1408. Additionally, the volume levels of rhythm guitartrack 1404, drum track 1410 and vocal track 1412 are set to a mediumvolume. These various track settings, corresponding to positions offader bars 1440, are selected using composition rules 350 (see FIG. 3)to achieve a desired intensity level while maintaining musicalintegrity.

In the second user state 1432 the user may be jogging, or walkingquickly, and therefore has a moderate activity level. To accommodatethis increase in activity, composition system 102 unmutes bass track1408 and further increases the volume of rhythm guitar track 1404, drumtrack 1410 and vocal track 1412. This increases the intensity of thecurrent song segment from low to medium.

Finally, in the third user state 1434, the user may be running andtherefore has a high activity level. In response to this increase inactivity, composition system 102 unmutes lead guitar track 1402 andkeyboard track 1406 and sets the volume of all the tracks to the maximumvalues (or close to maximum values). This increases the intensity of thecurrent song segment from medium to high.

As previously discussed, the decisions to mute or unmute particulartracks and the timing at which the tracks are muted or unmuted are madeby composition system 102 according to composition rules 350. Inparticular, the entry and/or exit of tracks is managed to ensure thatvarious desirable musical characteristics, such as intensity, tempo,pitch, and key as well as other possible musical characteristics, aremaintained or varied in a smooth manner without undesirable breaks,jumps or interruptions. Thus, for example, the intensity of the song canbe gradually increased without creating abrupt changes in tempo, pitchand key, which would be undesirable for the user.

In some embodiments, composition system 102 may be configured to bypass,or skip, some segments of a song to arrive sooner at a segment having adesired intensity. One possible example of such an embodiment isschematically shown in FIG. 15. Referring to FIG. 15, a current segment1502 is currently being played. This segment is a low intensity segmentand may generally be played for a user during low intensity activitiessuch as walking.

In response to a sudden increase in user activity, composition system102 may determine that a high intensity song segment is needed. In thisexemplary embodiment, composition system 102 determines that targetsegment 1504 has the desired high intensity. However, jumping directlyto target segment 1504 in this case would produce a jarring musicaltransition. Instead, composition system 102 determines that intermediatesegment 1512, which is a segment just previous to target segment 1504,has a similar musical structure to current segment 1502. Therefore,composition system 102 generates a musical path or musical sequence 1510through the song in which composition system 102 jumps from the end ofcurrent segment 1502 to the beginning of intermediate segment 1512, andalso bypasses a plurality of low intensity segments 1514. Fromintermediate segment 1512 there is already a natural musical transitionto target segment 1504. Thus, the musical sequence 1510 is seen tocomprise a sequence of song segments that is different from the normalsequence of the song, and which facilities moving more quickly betweensegments having varying intensities.

FIG. 16 is an embodiment of a process for moving between song segmentsof different intensities in a way that maintains musical coherence andavoids abrupt breaks or transitions in one or more musical attributes.As previously discussed, in some embodiments, one or more steps of theprocess can be performed by composition system 102. However, in otherembodiments, some steps could be performed by any other associatedcomponent, device or system. Moreover, some steps may be optional inother embodiments.

In step 1602, composition system 102 may determine a current activitylevel using information from one or more sensors. Next, in step 1604,composition system 102 may compare the activity level to the intensityof the current song segment. In step 1606, composition system 102determines if the activity level matches the intensity of the currentsong segment. If not, composition system 102 proceeds to step 1608 andcontinues playing the song without adjustment.

If there is a mismatch between activity level and song intensity in step1606, composition system 102 may move to step 1610. In step 1610,composition system 102 finds at least one target song segment that has amatching intensity for the current activity level. Next, in step 1612,composition system 102 generates one or more musically coherentsequences of segments, where each sequence starts with the currentsegment and ends with the target segment. Each sequence thus provides apath through the song from the current segment to the target segment. Instep 1614, composition system 102 may play the shortest sequence fromthe set of sequences found in step 1612. This allows composition system102 to transition to a song segment with an intensity that matches theuser activity in the shortest time possible. This helps increase theresponse of the system to changes in user activity.

Embodiments can include provisions to facilitate automaticallytransitioning between segments of different intensities. FIGS. 17 and 18illustrate schematic views of a song organized as a series of songsegments 1702 (in this case, ordered from segment 1 to segment 16). Inaddition, the embodiment includes a universal transition segment 1704,which acts as a means for connecting any two song segments in amusically coherent way. Thus, in the example of FIG. 17, a compositionsystem 102 can transition from segment 1710 to segment 1712(corresponding to the 1^(st) segment and the 11^(th) segment,respectively) via universal transition segment 1704. Likewise, in theexample of FIG. 18, composition system 102 can transition from segment1714 (the 7^(th) segment) to segment 1716 (the 12^(th) segment) by wayof universal transition segment 1704.

A universal transition segment can be created in a variety of differentways. In some embodiments, a universal transition segment could be apredetermined musical segment that is designed to have maximum musicalcompatibility with a variety of possible musical segments. In otherembodiments, a universal transition segment could be generated usinginformation from a particular song, thereby ensuring the universaltransition segment is maximally compatible with the particular segmentsof that song. Moreover, a universal transition segment could have anylength and tempo, and could include one or more instrumental or voicetracks.

Although the current embodiment illustrates the use of a singleuniversal transition segment, other embodiments could use one, two, ormore universal transition segments. Thus, when transitioning between twosegments, a composition system could select the best universaltransition segment that fits with the two segments from a set ofuniversal transition segments.

While the embodiments discuss playback of music information that hasbeen adjusted according to sensed information and various compositionrules, it will be understood that similar principles may likewise applyfor systems that record music information for playback at a later time.Thus, a composition system could be used to generate new musicalcompositions that are stored in one or more types of media, includingdigital files, CDs, tapes or other kinds of media.

While various embodiments have been described, the description isintended to be exemplary, rather than limiting and it will be apparentto those of ordinary skill in the art that many more embodiments andimplementations are possible that are within the scope of theembodiments. Accordingly, the embodiments are not to be restrictedexcept in light of the attached claims and their equivalents. Also,various modifications and changes may be made within the scope of theattached claims.

What is claimed is:
 1. A method of adjusting the playback of audioinformation, comprising: playing a set of audio tracks; retrieving a setof composition rules; receiving user activity information from at leastone sensor configured to detect movements of a user and determining auser activity level from the user activity information; determining atarget song intensity corresponding to the user activity level; andcontrolling the set of audio tracks to achieve the target songintensity.
 2. The method according to claim 1, wherein controlling theset of audio tracks includes muting and unmuting one or more audiotracks in the set of audio tracks.
 3. The method according to claim 2,wherein controlling the set of audio tracks includes controlling therelative volume of one or more audio tracks in the set of audio tracks.4. The method according to claim 2, wherein the set of composition rulesare used to determine the timing at which one or more audio tracks fromthe set of audio tracks are muted and unmuted.
 5. The method accordingto claim 1, wherein each audio track in the set of audio trackscorresponds to a different instrument.
 6. The method according to claim1, wherein the at least one sensor is associated with an article offootwear worn by the user.
 7. A method of adjusting the playback ofaudio information, comprising: playing a song, the song comprising aplurality of song segments that are sequential in time and the songfurther comprising a set of audio tracks that may be playedsimultaneously; retrieving a set of composition rules; receiving useractivity information from at least one sensor configured to detectmovements of a user; determining a user activity level from the useractivity information while a first song segment is being played; findinga second song segment with a song state that matches the user activitylevel; and using the composition rules to compose a musical transitionfrom the first song segment to the second song segment.
 8. The methodaccording to claim 7, wherein using the composition rules to compose themusical transition includes adjusting the entrance and exit of one ormore audio tracks from the set of audio tracks during the musicaltransition.
 9. The method according to claim 7, wherein using thecomposition rules to compose the musical transition includes selecting atransition pattern.
 10. The method according to claim 9, wherein thetransition pattern is an attack pattern.
 11. The method according toclaim 9, wherein the transition pattern is a decay pattern.
 12. Themethod according to claim 7, wherein the song state corresponds to anintensity of the song.
 13. The method according to claim 7, wherein theset of composition rules includes a set of user preferences that can beset by the user.
 14. The method according to claim 7, wherein the set ofcomposition rules includes at least one rule determining when two audiotracks from the set of audio tracks can be played together.
 15. Themethod according to claim 7, wherein the musical transition includes atleast one segment from the plurality of song segments.
 16. The methodaccording to claim 15, wherein composing the musical transition includesadjusting the composition of audio tracks from the set of audio tracksin the at least one segment.
 17. A method of adjusting the playback ofaudio information, comprising: playing a song, the song comprising aplurality of song segments that are sequential in time; receiving useractivity information from at least one sensor configured to detectmovements of a user; determining a user activity level from the useractivity information while a first song segment is being played; findinga second segment of the song with a song state that matches the useractivity level; retrieving a universal transition segment, wherein theuniversal transition segment can be played in sequence with any of theplurality of song segments without creating abrupt musical transitions;playing the universal transition segment after the first song segment;and playing the second song segment after the universal transitionsegment in order to create a transition between the first segment andthe second segment.
 18. The method according to claim 17, wherein theuniversal transition segment is generated by analyzing the plurality ofsong segments.
 19. The method according to claim 17, wherein theuniversal transition segment is configured for use with multipledifferent songs.
 20. The method according to claim 17, wherein theuniversal transition segment is one of a plurality of universaltransition segments, and wherein the method includes retrieving andusing two or more universal transition segments from the plurality ofuniversal transition segments.